Caudebec en Caux, immortalised in a painting by the French Impressionist Eugene Boudin, was for a long time the site of an impressive tidal bore, the mascaret - created by the force of the rising tide meeting the river in its downward flow, a wave ran upstream along the river at a speed of 25 kilometres per hour. Sadly - though not for mariners trying to navigate the river - the deepening of the river in 1964 put an end to this phenomenon.